code: def pool(self, F, x, size):
      return F.contrib.AdaptiveAvgPooling2D(x, output_size=size)
  
imports: from mxnet.gluon import nn
  from mxnet.context import cpu
  from mxnet.gluon.nn import HybridBlock
  from .segbase import SegBaseModel
  from .fcn import _FCNHead
label_desc: Use image node_id 2 for calling the _PyramidPooling obj's underlying member method code with example usage: obj.pool(F, x, size) and returns: F